Door latch



Feb. 9, 1960 G. WARTIAN 2,924,087

DOOR LATCH Filed July 22, 1957 2 Sheets-Sheet 1 INVENTOR.

Feb. 9, 1960 G, WARTlAN 2,924,087

DooR'LATcH Filed July 22, 1957 2 Sheets-Sheet 2 INV ENTOR.

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United Staates Patent DOOR LATCH George Wartian, Detroit, Mich., assgnor to Wartian Lock Company, St. Clair Shores, Mich., a corporation of Michigan Application July 22, 1957, Serial No. 673,211

1 Claim. (Cl. 70-135) This invention relates to a door latch and lock construction and has particular reference to a rotary bolt type of door latch having an improved latching and locking mechanism.

A principal object of the invention is to provide a new and improved door latch.

A further object of the invention is to provide a door latch of the rotary bolt type having an improved locking mechanism.

Another object of the invention is to provide a door latch and lock which is compact and economical to manufacture and install on a door.

Other vand further objects of the invention will be apparent from the following description and claims and may be understood by reference to the accompanying drawings, of which there are two sheets, which by way of illustration show a preferred embodiment of the invention and what I now consider to be the best modein which I have contemplated applying the principles of my invention. Other embodiments of the invention may be used without departing from the scope of the present invention as set forth in the appended claim.

. In the drawings:

Fig. 1 is a fragmentary elevational view of a door having the improved door latch applied thereto;

Fig. 2 is a side elevation of the latch;

Fig. 3 is a view taken on line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a sectional view taken on line 5-5 of Fig. 3;

Fig. 6 is a fragmentary view similar to Fig. 3 but showing the latch in its locked position;

Fig. 7 is a fragmentary view similar to Fig. 5 showing the latch in its unlatched position; and

Fig. 8 is a view similar to Fig. 5 showing the latch in its locked position.

The latch is shown in Fig. 1 applied to a door 10 which is hinged at one edge 12 within a door frame 14 having a keeper or strike plate 16 secured thereon. The latch includes a casing 18 enclosing the latch mechanism and adapted to be secured on the inner side of the door 10, an operating lever 20 in the form of a handle for operating the latch and a handle 22 adapted to be applied to the other side of the door and including an actuating element 24 projecting through the door for operating the latch mechanism.

The casing 18 is provided with anges 26 receiving screws 28 for securing the casing on the door adjacent its edge. The latch is of the rotary bolt type and includes a rotary bolt 30 which cooperates with the keeper 16, the bolt 30 and the keeper 16 being provided with complementary teeth 32 and 34 respectively. The bolt 30 and the keeper 16 are shown in Fig. 4 in their latched position in which one of the teeth 32 on the bolt is disposed between the teeth 34 on the keeper.

The casing 18 has an opening 36 in the wall thereof which is applied to the door and side walls 38 and 40. The wall 40 is provided with a recess 42 in which the rotary bolt 30 is disposed, the bolt being secured on a pin 44 which is journaled in the wall 40 of the casing.

As shown in Fig. 3, the keeper 16 includes a plate por-y tion 46 secured to the door frame and the teeth 34 projecting into the recess 42 in the casing wall 40 for cooperation with the bolt 30.

A ratchet 48 is secured on the inner end of the pin 44 for rotation with the bolt 30. The ratchet 48 is provided with a series of teeth 50, one of which is adapted to engage the upper end of a pawl 52 to prevent rotation of the ratchet 48 and the bolt 30 in a clockwise direction as viewed in Fig. 5. The pawl 52 is pivoted in the casing on a pin 54 and a spring 56 is wrapped around a pin 58 and has one end 60 reacting against the casing 18 and its other end 62 reacting against the upper end of the pawl 52 to urge the pawl into engagement with the ratchet. When the door is swung to its closed position, the teeth 32 on the bolt 30 will engage the teeth 34 on the keeper 16, thereby rotating the bolt 30 in a counterclockwise direction as viewed in Figs. 4 and 5. Rotary motion of the bolt and the ratchet in such direction is permitted since the teeth 50 on the ratchet will ride over the upper end of the pawl 52 to pivot the pawl against the spring 56. Engagement of the ratchet 48 by the pawl 52 Will prevent reverse rotation of the ratchet and bolt, thereby retaining the door in its latched position.

The handle 20 is in the form of a lever pivoted within the casing 18 on a pin 64 and extending outwardly from the casing through a slot 66 in the casing. The operating lever or handle 20 is provided with a suitable projection which may be a screw 68 as illustrated in the drawings. The projection 68 engages the pawl 52 above its pivot pin 54 and depression of the handle 20 will pivot pawl 52 out of engagement with the ratchet 48 to permit the latter and the rotary bolt 30 to `freely rotate in a clockwise direction, as viewed in Figs. 4 and 5', to permit the door to be opened. As soon as the handle 20 is released, the spring 56 will return the pawl 52 into engagement with one of the teeth 50 on the ratchet 48. The handle 20 may comprise merely a manual operable or, as illustrated, may include a horizontally disposed bar 70 secured at one end to the handle 20 and at its other end to a lever 72 pivoted adjacent the opposite edge of the door 10.

The handle 22 which is applied to the outer side of the door includes a handle portion 74 and a casing portion 76 having a recess 78 receiving a spring 80 which reacts against a shoulder 82 formed on a sleeve 84. The collar 82 has integral projections received within keyways 86 formed in the recess 78 so that the sleeve 84 and its collar 82 are axially slidable but non-rotatable within the casing portion 76. A plate 88 closes the open end of the recess 78 and the spring 80 reacts between the plate 88 and the collar 82 to urge the latter and the operating stem 24 to their retracted positions or away from the latch mechanism contained Within the casing 18. A conventional type cylinder lock, the details of which are not shown, may be received within sleeve 84 and the end of stem 24 is suitably secured to the rotatable part of the cylinder lock so that the stem 24 may be rotated when the lock is operated by a key indicated at 90. The actuating stem 24 is therefore axially slidable upon manual depression of the sleeve 84 and the lock cylinder contained therein, and it may be rotated in either direction by the lock mechanism.

The inner end 92 of the stem 24 extends into the casing 18 for engagement with the pawl 52. The pawl 52 has an intermediate portion 94 and a lower end 96 lying adjacent the side wall 38 of the casing 18. The inner end 92 of the stem 24 is normally spaced a slight distance from the intermediate portion 94 of the pawl 52 but upon depression of the stem 24 by the sleeve 8,4 the pawl is engaged at the intermediate portion 94 and Patented Feb. 9, 1960' pivoted out of engagement with the ratchet 4S to free the same and the rotary bolt 30 for rotation to permit the door to be opened. Thus the pawl 52 may be actuated to disengage the ratchet 48 from either side of the door.

A locking element 100 is pivoted in the casing y18 on a pin 102 and includes a manually engageable thumb piece 104 projecting outwardly through a slot 106 in the casing 18. The locking element 100' is provided with three integral arms 108, 110 and 112. The first arm 108 has a laterally turned end 114 which is adapted to be positioned between the portion 94 of the pawl 52 and the inner end 92 of the stem 24;. The locking element is shown in Figs. 3 and 5 in its unlocked position in which the end 92 of the stem 24 may engage the portion 94 on the pawl 52. When the locking element 100 is moved to its locking position shown in Figs. 6 and 8, the end 114 of the rarm 10S is disposed in the path of the end of the stem 24 to prevent actuation of the pawl 52 by the stem. The inner end of the stem is provided with an arm 116 which is adapted to engage the underside of a triangular shaped cam 118 formed on the end of arm 112. When the stern 24 is rotated by the lock mechanism, the arm 116 will engage the camshaped end of the arm 112 on locking element 100 to pivot the locking element to its locked position. When the stem is rotated in the opposite direction by the keyoperated lock, the arm 116 will engage the upper cam surface vformed on the end of the arm 112 to pivot the locking element from its locked to its unlocked position. The locking element 1%0 thus may be moved between its locked and unlocked positions from the outer side of the door through the key-operated locking mechanism.

The locking element 100 has its third arm 110 adapted to engage behind the lower end 96 oit the pawl 52 when the locking element is in the locked position. The pawl 52 cannot' then be actuated from the outer side of the door except through the key-operated lock means, but actuation of handle will disengage the pawl 52 from the ratchet and the locking element will be returned to its unlocked position through engagement of the lower end 96 of the pawl with the arm 110 on the `locking element.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modcation, and I therefore d0 not to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claim.

I claim:

A door latch of the rotary bolt type, comprising a casing adapted to -be secured on one side of a door, said casing having a recess in the side wall thereof, a rotary latch bolt journaled in said casing and disposed in said recess, a ratchet rotatable with said bolt and disposed within said casing, a pawl pivoted in said casing and engageable with said ratchet to prevent rotation of said ratchet and bolt in one direction, spring means urging said pawl into engagement with said ratchet, a handle pivoted in said casing and engageable with said pawl to disengage the latter from said ratchet, an operating member slidably and rotatably mounted on the other side of the door and manually depressible into engagement with said pawl to disengage the latter from said ratchet, a locking element pivoted in said casing, said locking element having a manually engageable portion extending outwardly through said casing so as to be accessible from said one side of the door for moving said locking element between locked and unlocked positions independently of movement of said handle, said element having an arm adapted to Ibe positioned between said operating member and said pawl in said locked position to prevent engagement of said pawl by said member, said locking element having a second arm engageable by said pawl upon actuation of said pawl by said handle to pivot said locking velement from its locked to its unlocked position, and key-operated lock means for ro. tating said operating member, said locking, element having a third arm engageable by said member upon rotation thereot` by said lock means to pivot said locking element between said locked and unlocked positions.

References Cited in the file of this patent UNITED STATES PATENTS 1,738,338 Wells Dec. 3, 1929 2,655,025 Marple Oct. 13, 1953 2,738,212 Wise Mar. 13, 1.956 2,767,010 Norman Oct. 16, 1956 2,797,571 Bergman July 2, 1957 

